Sheep Eye Dissection Lab

On Thursday, the 17th, my biology class did an interesting lab: Sheep Eye Dissection! I'd heard stories from my mother and father (both biologists) about their cow/sheep eye dissections and so I thought I pretty much knew what to expect. Most of the things that I'd heard about did happen, the black liquid squishing forth once the cornea had been punctured, the little gooey jelly bag inside the eye, and the odd, unappetizing smell of the whole affair. But somethings you just have to do yourself to really believe them. For example, I'd heard that the sclera was really hard and that the cornea would be tough to cut through, but I only really understood how tough those two layers were once I was hacking at them with a scalpel myself. However, one thing that was really unexpected, and really quite lovely, was the clean, mother-of-pearl retina, with it's blue-green-purple Ty-dye swirl of colors. It was so thin and fragile, I did my best to not tear it too much, but even just touching it slightly with the tip of my scalpel marred the hidden mosaic.



I was quite glad that we had a guest optometrist come and talk to us first, before our lab, because I understood what I was looking at much more, and didn't constantly have to be checking which thing was what on the cross section on our worksheets. Dr. Fong did a very nice job of getting our sometimes-inattentive class to listen and understand something about what she did and how she did it. She talked to us about all the parts of the eye; cornea, iris, lens, optic nerve, pupil, retina, vitreous humor, aqueous fluid, and the sclera, what caused near/far sightedness and what an optometrist looks at to find that information. It was interesting to hear what exactly the optometrist is looking for in an eye exam, because I've had several, but the only information I'm ever looking for is if I need glasses. The photographs of the eyes that she showed us were somewhat familiar to me because I've seen pictures of my own eyes like that, but now I know a bit more about what my optometrist sees when he looks at them. After all they're just orangey blobs to me, but they give him a wealth of information I'd never guessed a simple picture could. Thanks Mr. Olson, and Dr. Fong, it was very enjoyable.

Here is an online tutorial to learn the anatomy of the eye, with descriptions of all it's parts : http://www.jburroughs.org/science/resources/skeleton/eye/diagramtutorial.html

And here is a youtube video of an actual sheep eye dissection, I recommend turning the volume off because none of the people say anything interesting, but is has good images.
http://www.youtube.com/watch?v=WL9u0NIUspI&feature=related